Patients with heart failure have frequent ventricular arrhythmias which are responsible for a sudden death rate of approximately 40-50% in this patient population. d-Sotalol has been the only agent to improve the recurrence of arrhythmias in patients with left ventricular dysfunction, however most antiarrhythmic medications including d-Sotalol have negative inotropic effects which may be poorly tolerated in patients with depressed left ventricular function. The effects and tolerability of this drug will be studied.